4.9-stable review patch. If anyone has any objections, please let me know.
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From: Vlad Tsyrklevich vlad@tsyrklevich.net
[ Upstream commit 4f7f4dcfff2c19debbcdbcc861c325610a15e0c5 ]
The 'num_sge' variable is verfied to be smaller than the 'sge_count' variable; however, since both are user-controlled it's possible to cause an integer overflow for the kmalloc multiply on 32-bit platforms (num_sge and sge_count are both defined u32). By crafting an input that causes a smaller-than-expected allocation it's possible to write controlled data out-of-bounds.
Signed-off-by: Vlad Tsyrklevich vlad@tsyrklevich.net Signed-off-by: Doug Ledford dledford@redhat.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/infiniband/core/uverbs_cmd.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-)
--- a/drivers/infiniband/core/uverbs_cmd.c +++ b/drivers/infiniband/core/uverbs_cmd.c @@ -2491,9 +2491,13 @@ ssize_t ib_uverbs_destroy_qp(struct ib_u
static void *alloc_wr(size_t wr_size, __u32 num_sge) { + if (num_sge >= (U32_MAX - ALIGN(wr_size, sizeof (struct ib_sge))) / + sizeof (struct ib_sge)) + return NULL; + return kmalloc(ALIGN(wr_size, sizeof (struct ib_sge)) + num_sge * sizeof (struct ib_sge), GFP_KERNEL); -}; +}
ssize_t ib_uverbs_post_send(struct ib_uverbs_file *file, struct ib_device *ib_dev, @@ -2719,6 +2723,13 @@ static struct ib_recv_wr *ib_uverbs_unma ret = -EINVAL; goto err; } + + if (user_wr->num_sge >= + (U32_MAX - ALIGN(sizeof *next, sizeof (struct ib_sge))) / + sizeof (struct ib_sge)) { + ret = -EINVAL; + goto err; + }
next = kmalloc(ALIGN(sizeof *next, sizeof (struct ib_sge)) + user_wr->num_sge * sizeof (struct ib_sge),